Field of the Invention
The invention relates to an electric tool, such as a hammer drill, an impact drill, an impact wrench, or the like, where a brushless motor is used as a driving source.
Description of Related Art
Electric tools, particularly electric striking tools, such as hammer drill have a mechanical section that is complicated and has a significant amount of components. To maximize the performance of the mechanical section to its full extent, it is very important for the mechanical section to match motor performance.
For example, to solidly match the mechanical section with motor performance, motor speed control utilizing electronic control is applied to suppress variation of a target motor speed within a range of plus or minus a few percentage points. In addition, in order to continuously perform demanding operations, a rated power input (W) of the device is also important. Based on a target value, motor winding, thickness of motor core lamination, or the like may be modified.
Regarding the shape of motor core, a standard motor core capable of achieving average performance in various devices is adopted.